Developmental Consequences of Sexual Conflict on Female Behavior, Cognition and the Brain

生命早期的社会互动对行为模式、认知能力和大脑的发展有很大的影响。对人类的研究发现了早期经历与认知行为特征之间的相关性。这个项目将通过剑尾鱼的操纵实验来测试这些关系。先前对鱼类的研究已经确定，一种特殊的压力社会互动被称为性冲突（雄性和雌性在交配率上存在分歧），可以导致雌性大脑体积的增加。与此同时，其他研究表明，必须驾驭不同类型的社会互动（也称为社会复杂性）可能会提高认知能力。这项研究将通过控制在一个表现出社会复杂性和性冲突的鱼类系统中饲养的社会条件来检验这两个相互矛盾的假设。有三种不同类型的剑尾雄鱼，它们代表着对雌性的不同程度的性冲突（高、低或中等的性冲突）。通过在不同类型雄性剑尾鱼的社会环境中饲养雌性剑尾鱼，研究人员可以量化性冲突和社会复杂性如何影响成年鱼的行为（包括焦虑、攻击和社交能力）、认知（学习能力），并确定大脑中哪些区域会因不同的社会经历而增长或减少。通过研究者的努力，她的研究将会对当地和全国的学生产生更广泛的影响，通过当地高中的推广计划和德克萨斯大学的新生研究计划课程，以及通过学生发起的全国媒体产品（YouTube）来进行这项研究。性冲突，即两性之间在最佳交配率上的不匹配，在动物中无处不在。虽然这种斗争的形态学结果已经得到了充分的研究，但对性冲突的行为和认知后果却知之甚少。在本研究中，研究者将通过实验研究剑尾鱼（Xiphophorus nigrensis）的性冲突对发育的影响，剑尾鱼有三种不同的雄性表型，代表了对雌性的不同程度的性冲突：求爱雄性（低冲突）、强制雄性（高冲突）和既求爱又胁迫的雄性（混合冲突）。雌性剑尾鱼从出生到成年早期将在五种社会环境中的一种中长大，这些环境在性别冲突和社会复杂程度上都有所不同。成年后，女性将参加广泛的测试，以确定社会经历如何塑造行为和认知特征。这些测试评估焦虑、社交和探索倾向以及联想学习、认知灵活性和社会认知能力。女性大脑将被检查，以确定社会环境如何影响不同大脑区域的发展和候选社会途径的受体分布，包括催产素和突触可塑性标记。本实验的结果将确定社会环境如何影响行为倾向的发展，并直接测试关于增强认知和大脑发展的竞争性假设（性冲突与社会复杂性）。它还将确定哪些大脑区域（专注于社会决策网络）在应对与冲突和复杂性相关的特定社会互动时经历不同的发展。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Social interactions during early life can have large impacts on the development of behavioral patterns, cognitive abilities and the brain. Research in humans has found correlations between early experiences and cognitive-behavioral traits. This project will test these relationships using manipulative experiments with swordtail fish. Previous research in fish has determined that a particular kind of stressful social interaction known as sexual conflict (where males and females disagree over mating rates) can lead to an increase in female brain size. Meanwhile, other research has suggested that having to navigate different kinds of social interactions (also known as social complexity) may result in enhanced cognitive capabilities. The research will test these two competing hypotheses by controlling social conditions during rearing in a fish system that exhibits social complexity and sexual conflict. There are three different types of swordtail males, which represent different levels of sexual conflict towards females (high, low or intermediate sexual conflict). By raising female swordtails in social environments that vary in the type of males present, researchers can quantify how sexual conflict and social complexity shape adult behaviors (including anxiety, aggression and sociability), cognition (learning abilities), and determine which brain regions grow or diminish in response to different social experiences. This research will have broader impacts that affect both local and national students through the investigator's efforts to incorporate her research into local high school outreach program and the Freshman Research Initiative course at the University of Texas, and through student-initiated national media products (YouTube) on this research.Sexual conflict, the mismatch in optimal mating rates between the sexes, is ubiquitous across animals. While the morphological consequences of this struggle are well-studied, less is known about the behavioral and cognitive consequences of sexual conflict. In this study, the investigator will experimentally examine the developmental effects of sexual conflict in the swordtail fish (Xiphophorus nigrensis), which has three alternative male phenotypes that represent different levels of sexual conflict towards females: courting males (low conflict), coercive males (high conflict), and males who both court and coerce (mixed conflict). Female swordtails will be raised from birth to early adulthood in one of five social environments that vary in levels of both sexual conflict and social complexity. At adulthood, females will partake in a broad range of assays to determine how social experiences shape behavioral and cognitive traits. These assays evaluate anxiety, sociability and exploratory tendencies as well as associative learning, cognitive flexibility and social cognition capabilities. Female brains will be examined to determine how social environment influences the development of distinct brain regions and receptor distribution of candidate social pathways including isotocin and synaptic plasticity markers. The results of this experiment will identify how the social environment influences the development of behavioral tendencies, as well as directly test competing hypotheses for enhanced cognition and brain development (sexual conflict versus social complexity). It will also identify which brain regions (focusing on the social decision-making network) undergo differential development in response to specific social interactions associated with conflict and complexity.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.